1. Field
Example embodiments relate to magnetoresistive elements and memory devices including the same.
2. Description of the Related Art
Magnetic random access memory (MRAM) is a memory device which stores data by using a resistance change of a magnetic tunneling junction (MTJ element. The resistance of the MTJ element depends on the magnetization direction of a free layer. In other words, when the magnetization direction of the free layer is identical with that of a pinned layer, the MTJ element has a low resistance value. When the magnetization direction of the free layer is opposite to that of the pinned layer, the MTJ element has a high resistance value. When the MTJ element has low resistance, the MTJ element may correspond to data ‘0’. When the MTJ element has high resistance, the MTJ element may correspond to data ‘1’. This MRAM attracts attention as one of the next-generation non-volatile memory devices due to its merits such as non-volatility, high-speed operation, and high endurance.
To increase a recording density of MRAM (i.e., to obtain a high-density MRAM), the size of the MTJ element needs to be reduced. However, when the width of the MTJ element is reduced to less than several tens of nanometers (nm), the intensity of a stray field generated from a pinned layer may be greatly increased, and thus may adversely affect the switching characteristics (i.e., magnetization inversion) of a free layer. Therefore, switching asymmetry of the free layer may occur and it may cause a serious problem in an operation of the MRAM. For this reason, it is not easy to increase the recording density of the MRAM to a certain level or greater.